Lighting is an art that when skillfully applied may enhance the color, shadow, and texture of images for viewing and photography. Special techniques are often needed for optimal results, particularly if images are magnified. For instance, certain image characteristics may be improved by aiming light on a given specimen from two or more lights sources simultaneously. Types of lighting sources are numerous; however advances in light-emitting diode (LED) technologies over the past decade have resulted in light sources with relatively low heat load, small size, and minimal energy requirements compared to many other lighting technologies. Subsequently, LEDs are a natural choice for enhanced imaging, particularly when multiple sources are prescribed.
Enhanced imaging may be fairly unpredictable for a given specimen and experimentation with specific placement of light sources is often required. Indeed, some image details are only revealed with careful adjustment to the intensity and angle of light. Depending on the features to be enhanced, light sources that are too intense may be made more distant or positioned obliquely for better results. Yet, oblique positioning will not always improve contrast. Instead desired clarity may require fairly concentrated direct, front or back lighting.
At the same time, direct and concentrated lighting may produce unwanted shadows, reflections, and glare. These and other artifacts from light that is overly intense can be minimized if the light is dimmed or diffused. Problems from too much light may also be corrected with shades, filters that help limit specific wavelengths, or with polarized lenses that can scatter and soften the light as required per application.
Imaging equipment incorporating features for experimenting with lighting adjustments are plentiful. Diffusers, reflectors, variable intensity light sources, and positioning adjustments are typically incorporated into light microscopes. Annular light rings are also combined to provide adjustable light quality from devices having multiple sources of light.
An example of a state of the art lighting device is found in U.S. Patent Publication No. 2011/0026113 of Paulus. The publication's disclosure describes a device incorporating a flexible and elastic reflector, moveable through different positions with respect to a sample placed on a microscope stage. The reflector houses multiple light sources in an annular arrangement and provides diffuse lighting at different distances and positions from the sample to the extent that the reflector is configurable.
Still, there is a need to further advance lighting for close imaging of small specimens. An apparatus with the capacity to position multiple light sources at varying distances and angles around specimens that also offers the operator the ability to independently adjust individual light sources would make illuminating specimens easier to optimize while providing easy access to staged specimens. In accordance with the present invention, related embodiments of a lighting apparatus and methods improve upon advantages of known devices.